Bismuth molybdate (Bi2MoO6) is a typical layered perovskite composite oxide, consisting of [Bi₂O₂]²⁺ layers and [MoO₄]²⁻ octahedra, with the perovskite-type [MoO₄]²⁻ forming a shared octahedral structure. This configuration facilitates efficient electron ionization and endows the material with excellent gas sensitivity. This behavior, coupled with its moderate band gap (2.6 eV), enables the material to detect phosphine with high sensitivity at room temperature. Our simulations show that the stability and electronic properties of bismuth molybdate make it a promising material for developing reliable and efficient phosphine sensors. Bi₂MoO₆ can be formed into nanoparticles with various structures, such as nanosheets, flower-like, walnut-like, and yolk-shell structures, depending on the synthesis strategy. For example, Liu et al. introduced 5% Ag into flower-like Bi₂MoO₆ via a two-step solvothermal method and glucose reduction, achieving an NH₃ detection limit of 50 ppb at room temperature. Ma et al. synthesized a Bi₂MoO₆/ZnO composite material via a secondary hydrothermal synthesis, which exhibited excellent sensing performance for n-butanol at 270°C. Zhang et al. prepared Bi₂MoO₆ nanospheres on a walnut nanosheet substrate, successfully detecting 0.1 ppb H₂S at 133°C, with minimal sensitivity to humidity changes. These findings further confirm the sensing potential of Bi₂MoO₆ as a ternary gas-sensing material. However, few studies have focused on the gas-sensing performance and response mechanism of Bi₂MoO₆ at room temperature.
